A recent study published in Scientific Reports evaluated the cumulative incidence and the risk of major adverse cardiovascular events (MACE) following transient ischemic attack (TIA) or ischemic stroke (IS).
Study: Long-term risk of major adverse cardiovascular events following ischemic stroke or TIA. Image Credit: H_Ko/Shutterstock.com
Background
Stroke is one of the leading causes of disability and death worldwide. Besides, individuals surviving the acute phase are at risk of cardiovascular event recurrence. The risk of cardiovascular events appears similarly high after acute TIA. A study from 2011 reported that the incidence of IS recurrence was 11% after one year and 26.4% after five years.
Recent studies estimate the incidence of recurrent IS at 3.6% to 6% after one year and 9.5% to 16% after five years. Longitudinal data on the risk of new cardiovascular events following TIA or IS are scarce.
Therefore, up-to-date information on the risk of new events and risk factors is necessary, given the growing need for secondary preventative measures.
About the study
In the present study, researchers assessed the risk and the cumulative incidence of MACE after IS or TIA and identified the factors linked to higher risks. TIA and stroke patients were identified from a randomized controlled trial.
Patients with TIA or stroke admitted to Östersund Hospital in Sweden were screened between 2010 and 2013 for participation in the trial. All TIA and stroke survivors were included for analysis.
MACE was the composite of type 1 acute myocardial infarction (AMI), IS, and cardiovascular death, whichever occurred first. IS was defined as an acute episode of global or focal cerebral, retinal, or spinal dysfunction due to the infarction of central nervous system (CNS) tissue.
A stroke was an episode of focal cerebral dysfunction with brain infarction, with symptoms subsiding within 24 hours. A TIA was the same as a stroke except without brain infarction.
AMI or stroke followed by death within 30 days was classified as cardiovascular death. Baseline characteristics were obtained through interviews and medical records. Subjects were followed for recurrent events until 2017.
Cardiovascular events were identified by reviewing discharge records and complementarily screening in-patient registers. The team used Cox proportional hazards regression to identify MACE-associated factors.
Findings
The study comprised 1,535 patients with a median age of 77. The index event was TIA in 29% of patients and IS in 71%. Most patients were males (55.6%).
Overall, 685 deaths occurred in the follow-up period, including 225 within the first year after discharge. Over 49% of IS patients and 33.3% of TIA cases died. Approximately 44% of deaths in IS patients and 31% in TIA cases were cardiovascular deaths.
Subjects were followed up for a median of 4.4 years. During this period, MACE occurred in 28.7% of patients; cardiovascular deaths (47.7%) and IS (42.7%) were the most prevalent MACE. Type 1 AMI occurred in 42 patients. The cumulative incidence of MACE in the first year post-discharge was 12.8% but 35.6% at the end of the follow-up.
It was significantly higher in IS patients at either time than in TIA subjects. At the end of the follow-up, the cumulative incidence of IS, AMI, and cardiovascular deaths was 14%, 4.1%, and 25.3%, respectively.
Around 68% of cardiovascular deaths were recorded within 90 days. The incidence of cardiovascular deaths was higher in IS cases than in TIA patients.
AMI or IS incidence was not different between TIA and stroke patients. The multivariable Cox regression model revealed age, glomerular filtration rate (GFR) < 60 ml per minute, prior IS, AMI, congestive heart failure, atrial fibrillation, IS as an index event, and impaired functional status at discharge as factors associated with increased MACE risk.
Conclusions
The researchers estimated the cumulative incidence of MACE following TIA or IS to be 35.6%. It was 12.8% in the first year after discharge.
IS patients exhibited a significantly higher risk of MACE than TIA cases. There was an association between established risk factors for cardiovascular events and increased MACE risk.
Notably, the risk of IS was similar after stroke or TIA. Cardiovascular deaths and IS were the most prevalent events, and their risk was particularly increased early in the follow-up period. The study’s limitations include the small sample size, the use of hospital records, and the single-center cohort design.
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